Knife-grinding machine



(No Model.) 2'She ets -Sheet 1.

G. B. SNOW A. SHERMAN. KNIFE GRINDING MACHINE. No. 570,966. Patented Nov. 10,1896.

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(No Model.) 2 Sheets-Sheet 2.

C. B. SNOW 8:; O. A. SHERMAN.

' KNIFE GRINDING MACHINE.

No. 570,966. Patented Nov. 10, 1896.

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UNITED STATES PATENT OFFICE.

CHARLES E. SNOW AND CI-IAUNCEY A. SHERMAN, NORWICH, CONNECTICUT.

KNIFE-GRINDING MACHINE.

SPECIFICATION forming part of Letters Patent No. 570,966, dated November 10, 1896.

Application 1116a u e 19, 1895.

Serial No; 553,355. (No model.)

To all whom it may concern.-

Be it known that we, CHARLES B. SNOW and CHAUNCEY A. SHERMAN, citizens of the United States, residing at Norwich, in the county of New London and State of Connecticut, have invented certain new and useful Improvements in Knife-Grinding Machines,

of which the following is a full, clear, and exact description, whereby any one skilled in the art can make and use the same.

The within-described invention relates to machines used for grinding knives; and the particular object of our invention is to proor plan view of the device with one of the grinder-shafts broken in two and part of the mechanism removed. Fig. 2 is a detail View,

in vertical section,through the cam-shaft,with' parts broken away to show construction. Fig. 3 is an end view of the device. Fig. 4 is a detail view,in vertical section, through one of the grinder-shafts. Fig. 5 is a detail view showing a portion of the grinding-wheels with a knife-handle between the same.

In the accompanying drawings the letter ct denotes the base or frame of the machine, made of any convenient material, as iron, preferably cast to shape and provided with standards or legs b. The carriages c c are supported in the guideways cl d on the bed and are movable a limited distance toward and from a cam-shaft e, which is mounted in bearings f transversely across the center of the bed.

The carriages are held at the outer limit of their play by springs or by counterp'oiseweights and are connected, as by means of a rope or like flexible attachment f, to a treadle f by the use of which the carriages may be given a simultaneous movement toward an from each other.

The cam-shaft c has fast to it a pulley e, by means of which it may be driven by a belt from any suitable source of power, and to the shaft is also secured a number of cams g g .On each of the carriages c 0 there is mounted a table h h, preferably pivoted as by means of'a bolt 2', passing through the table and the carriage. 0n the inner edges of the table next to the cam-shaft a number of bearingrolls 7.: k Z Z are supported in position to be held in contact with the bearing-surfaces of the earns, the rollersl Z being appurtenant to :the cams g g and the rollers k to the cams g g Each of these cams is so shaped as to its bearing-surface as to not only cause the carriages to move towardand from the camshaft, but also to give to the tables a swinging movement on the pivot.

On each table there is mounted in suitable bearings a grinder-shaft m m, the outer end of each shaft supporting the grinding-wheels n n. Each of the grinder-shafts has a rotary and also a lengthwise sliding movement in the bearings, so as to cause the grinding-face to move'laterally back and forth across the surface of the article which is being ground.

'Each grinder-shaft is provided with a collar 01. which is adapted to rest against the outer surface of one of the bearings, and on the opposite side of the bearing a spiral spring 01 coiled about the shaft, is arranged to thrust, while the other end of the spring thrusts against an adjustable collar 41 secured to the shaft. The end of each shaft bears on the surface of a cam fixed to a shaft 0, arranged in suitable bearings lengthwise of the machine and provided with a pulley 0, which is driven by a belt from a countershaft. a lengthwise sliding movement is impartedto the grinder-shaft, the spring serving to keep the end of the shaft and the surface of the cam in contact.

A holder-shaft p is mounted in bearings 13 on a bracket fast to the frame, a cog-wheel p on the shaft meshing with a cog-wheel q fast to a shaft 8, also mounted in bearings and having a pulley e", bymeans of which the shaft is driven from a counter-shaft or other suitable source of power. The holder-shaft has a clamp 0, arranged to hold a knife .9, so that the handle will be located between the By the rotary movement of the cam adjacent faces of the two grinding-wheels n n, the axes of the wheels of the holder-shaft and of the cam-shaft being preferablyin'the'same plane.

Arest 15 projects fromv the table and is arranged so as to support the handle of the knife while it is being ground, the two grindin g-wheels turning toward each other and operating at the same time upon opposite sides of the handle.

WVhen the bearing-rolls on the carriages are in contact with the cams on the cam-shaft, the surfaces of the grinding-wheels are in contact with the surfacev of the knife-handle, and they are held in this position by means of a downward pressure upon the treadle.

The operation of the machine is as follows: A knife-blank with the handle as it comes from the forge is clamped in place in the holder-shaft with the handle projecting between the adjacent surfaces of the grindingwheels, as shown in Fig. 2 of the drawings. By a pressure upon the treadle the carriages are then moved toward each other and the bearing-rolls held in contact with the cams, the rotation of the cam-shaft changing the position of the cams and causing the carriages and the table supported thereon to take the position and to make the movements at the time and to an extent determined by the particular configuration of the cam-surfaces. These are so shaped as to cause the grindingwheels to remove the flash from the edges of the handle and to grind the surfaces to a uniform shape, each wheel backing up the other and the rest supporting the handle in its rotary movement. The restt includes a bracket fast to a fixed portion of the machine, which bracket extends outward, so that a'verticallymovable part will be located between the faces of the grinding-wheels and directly underneath the handle 3 of the knife. In the form shown the yielding portion of the rest is supported by springs between it and the bracket and the shank of rectangular outline extends through an opening in the bracket and rests upon a cam borne on the shaft 6, the cam being so shaped as to time the vertical movements of the yielding portion as to keep in contact with the surface of the handle which is being ground. Starting with the handle in the position shown in Fig. 1 of the drawings, the rest is at the upper limit of its play, but as the handle turns, so as to present the edge upward and its flat surfaces to the grinding-wheels, the rest is allowed to fall, there being a slight play, so as to bring the supporting-springs into operation in the support of'the handle while it is being ground.

\Ve claim as our invention- 1. I11 a grinding-machine in combination with a frame having guideways, a cam-shaft mounted transversely of the frame, reciprocatin g slides borne on the frame, atable pivotally supported on the respective slides and having hearings in contact with the cams, means for holding the tables in contact wit-h the cams, grinder-shafts supported in bearings on each table and having a lengthwise i and rotary motion in the bearings, grindingwheels supported on each shaft, means for reciprocating the grinder-shafts, a rotary knife-holding clamp adapted to hold the knife with a portion extending between the opposing grindingsurfaces, and means for driving the respective shafts, all substantially as described.

2. In a grinding-machine in combination with a frame, guideways on the frame, a camshaft mounted transversely of' the guideways on the frame, reciprocating slides mounted on opposite sides of the cam-shaft and each supporting a table, a table pivotally supported on each slide and having hearings in contact with cams on the cam-shaft, means for holding the tables normally in contact with the cams, grinder-shafts supported on bearings on the respective tables, a rotary knife -holding clamp adapted to hold the knife with a portion extending between the opposing grinding-surfaces, a yielding rest arranged between the grinding-wheels and below the work, a cam mounted in contact with the work-rest and means for driving the several shafts, all substantially as described.

3. In a grinding-machine in combination with grinder shafts and grinding wheels borne thereon, the grinder-shafts supports, means for automatically imparting a lengthwise and also a sidewise swinging movement of the grinder-shafts, a working rest arranged between the grinding-wheels, the cam forming a positive support for the yielding rest and springs supporting the moving part of the work-rest, the work-holding clamp, and means for rotating the same, all substantially as described.

' CHARLES E. SNOW.

OHAUNCEY A. SHERMAN. \Vitnesses:

GEORGE E. PARSONS, SAMUEL D. OAULKINs. 

